Stock harmonic balancer
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Joined: Jul 2002
Posts: 181
From: North Platte, NE
Stock harmonic balancer
The shop tuning my car says that my SFI approved one from Jegs could be causing problems with the cam sensor?
Last edited by Injuneer; Jan 12, 2009 at 05:27 AM. Reason: "parts wanted" content deleted
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Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
The "cam sensor" is built in to the opti. Nothing that the SFI could be bothering. If you happen to mean the crank sensor, then it still would not bother it as long as the reluctor is in the right place.
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From: North Platte, NE
I would think the reluctor ring should be on right. There was only one way it would go on with it being keyed, then the hub tightens up against it. He's thinking aftermarket balancers cause vibration and destroy optisparks, but I thought that was the whole idea of an SFI approved one was to cause less vibration to help keep the crank in one piece. Correct me if I'm wrong.
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Joined: Dec 1969
Posts: 27,725
From: Little Rock, AR
I would think the reluctor ring should be on right. There was only one way it would go on with it being keyed, then the hub tightens up against it. He's thinking aftermarket balancers cause vibration and destroy optisparks, but I thought that was the whole idea of an SFI approved one was to cause less vibration to help keep the crank in one piece. Correct me if I'm wrong.
Yes, you would need a 96-97 hub to work with the reluctor to line up your serpentine belt properly.
Last edited by shoebox; Jan 12, 2009 at 02:41 PM.
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From: Hell was full so they sent me to NJ
SFI means it won't explode, or come flying off and kill someone. SFI does not cover performance characteristics, only safety. SFI doesn't care about your crank, only the driver and people nearby.
Add to that the fact that it is not a balancer, but a harmonic damper. Its damping the radial vibrations and resonance of the crank, not balancing it.
Add to that the fact that it is not a balancer, but a harmonic damper. Its damping the radial vibrations and resonance of the crank, not balancing it.
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From: Little Rock, AR
Thread Starter
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Joined: Jul 2002
Posts: 181
From: North Platte, NE
Well, I'm trying to get the graph from him, unfortunately he's about a 3 hour drive from me, so I'm waiting for him to email it if he can.
He says it pulls on the dyno to 5800 rpm like a normal car, graph looks normal, then after there's a dip then it pulls, then dips, then peaks around 6500 rpms, then has a bit of a missfire closer to 7000 rpms.
He also says that the intake manifold pressure drops when he mashes the gas. I've been told either theres an air intake restriction or valves could be to tight and not seating all the way and causing compression loss.
He thought maybe the balancer being aftermarket (Jegs brand) it could be messing with the crank / cam sensor. Don't ask me why, SFI approved, should be better than stock.
This all gets to be above my head from here, so I'm game for any input.
He says it pulls on the dyno to 5800 rpm like a normal car, graph looks normal, then after there's a dip then it pulls, then dips, then peaks around 6500 rpms, then has a bit of a missfire closer to 7000 rpms.
He also says that the intake manifold pressure drops when he mashes the gas. I've been told either theres an air intake restriction or valves could be to tight and not seating all the way and causing compression loss.
He thought maybe the balancer being aftermarket (Jegs brand) it could be messing with the crank / cam sensor. Don't ask me why, SFI approved, should be better than stock.
This all gets to be above my head from here, so I'm game for any input.
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Joined: Aug 2001
Posts: 407
From: Ft. Lauderdale, FL
"He also says that the intake manifold pressure drops when he mashes the gas"
when you hit the throttle, the blades open, and the map sensor should be at or near atmospheric pressure,which depending or where you are should be around 103 +/- a few kpa. so what do you mean when you say the pressure drops?
when you hit the throttle, the blades open, and the map sensor should be at or near atmospheric pressure,which depending or where you are should be around 103 +/- a few kpa. so what do you mean when you say the pressure drops?